1. Field of the Invention
This invention relates to a repair operational amplifier (ROA) circuit, especially to the ROA circuit and operating method thereof applied in a liquid crystal display panel.
2. Description of the Related Art
With the development of liquid crystal display technology, the liquid crystal display has been widely used in different regions. As shown in FIG. 1, when a liquid crystal display panel LCP displays a picture, there may be a line broken on the liquid crystal display panel LCP and the signal transmission will be failed. At this time, the liquid crystal display panel LCP needs a repair operational amplifier (ROA) circuit 1 to repair the broken line. However, since different lines (e.g., P1, P2) on the liquid crystal display panel LCP could be broken at different times, repairing paths of repair operational amplifiers ROP1 and ROP2 of the ROA circuit 1 could be also different. In addition, parasitic resistances and parasitic capacitances in the repairing paths could be different, so that signal transmission rates could be also different, as shown in FIG. 2, and the line repairing failure probability of the repair operational amplifier will be increased, errors will be occurred when the liquid crystal display panel LCP displays the picture. Especially, the variation of parasitic capacitance is more trouble than the variation of parasitic resistance because the variation of parasitic resistance can be overcome by increasing a line repairing diameter, but the variation of parasitic capacitance cannot be overcome by doing so.